Find flood defence structures near you (The National Flood Asset Database)

Culverts can be dangerous. Only trained professionals should go in culverts. You risk injury, drowning, poisonous gasses and becoming trapped if you go into a culvert. 

The National Flood Asset Database

The National Flood Asset Database records flood infrastructure in Wales, including embankments, walls, flood gates, culverts, and inlet screens (which catch debris).

You can search for these on the map below. The database includes:

  • type of structure
  • length
  • who maintains it (for example Natural Resources Wales or local authorities)
  • who owns it (for example Natural Resources Wales or local authorities)
  • an ID number you can quote in correspondence 

Check if you have a flood asset on your land

If a culvert or other structure runs through your property, you would own it from the point that that it enters your land to the point that it leaves. 

You are responsible for maintaining, repairing, and replacing flood assets on your land. Natural Resources Wales and local authorities maintain some flood assets, on a risk priority basis.

Check who owns and maintains flood assets in the map below: 

  • search for your address
  • left click on a flood asset on the map
  • click the 'right arrow' symbol
  • check the 'OWNER' and 'MAINTAINED BY' information

If the 'OWNER' is 'Private' or 'Third Party Owner' and the asset is on your land, you own it: 

Map contains Ordinance Survey data © Crown copyright and database rights 2021 100019741

If you have a flood asset on your land

If our map shows that you have a flood asset on your land but do not know where it is, or you are worried about its condition:

  • check the title deeds for your property 
  • check documents from your conveyancer
  • check who maintains the asset in the map above and ask them about its location and condition
  • search for a drainage professional to carry out a drain or culvert survey if the asset maintainer has no more information
  • contact your local authority or Natural Resources Wales to ask for more information about the asset

You can also check your flood risk by postcode or search on a map

Updates to the map of flood assets

We will regularly update the map above to improve the accuracy of the data. The position of flood assets is for general guidance only. At the moment:

  • some of the data may be inaccurate or out-of-date
  • some of the underground assets might not be known or recorded accurately

If you have any queries or concerns about location, maintenance, condition or records of flood assets, check with the owner or maintainer.

Local authorities must submit data to us so we can add their new flood assets to the National Flood Asset Database.

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